dixonk

iTrader: (8)

Okay I know the formula to determine overlap is {[(int+exh)/4]-LSA}*2 but say for instance my cam is going to be 244/247 with a 113+3 LSA. Now how would I calculate that?

Second question: I know overlap determines how bumpy and loud the cam will be so how do you use the overlap for a comparison?

Thanks,

Kevin

ramairJP

iTrader: (3)

Advance doesn't change the overlap, it just changes the ICL (when installed dot-to-dot). More overlap makes for a rougher idle.

ss1

iTrader: (32)

It would be the same overlap as a 113 cam. The cam would just have three degrees of advance ground in it. It would pick you up some low end compared to a straight up 113 cam. If you had an adjustable timing chain, you could make either cam work the same.

dixonk

iTrader: (8)

Oh okay thank you. So looking at this I am going to have 19.5 of overlap. How wicked is this cam going to be???

ramairJP

iTrader: (3)

Your 408 will absorb some of that overlap, but it'll still have a pretty rowdy idle. Should sound nasty

dixonk

iTrader: (8)

Good thats what I wanted to hear!

s346k

iTrader: (4)

in that 408 cid motor, i don't think it will be rowdy at all. that would be similar to an ls1 with a g5x3 on 110 lsa.

why the 113 lsa?

dixonk

iTrader: (8)

Thats what was spec'd out for me.

ramairJP

iTrader: (3)

I was thinking it would be similar to something with 10-14 degrees of overlap in a 346. An X3 on a 112 has a pretty healthy idle IMO. Maybe our definition of a rough or rowdy idle is different.

dixonk

iTrader: (8)

So it will sound like this?:

http://www.youtube.com/watch?v=4QNOq...eature=related

Thats a G5x3 with Corsa Touring like I have. Just hope it makes some power.

dixonk

iTrader: (8)

I am looking for angry sounding but not a pig to drive and crank up and drive. But power is still more important.

ramairJP

iTrader: (3)

That's a cold start/fast idle in that video. If you tune the idle speed down in the 900 range it should sound like a pro stocker at idle.

dixonk

iTrader: (8)

Cool beans man! Thanks.

Shawn MacAnanny

iTrader: (12)

mines a 110+4, 106ICL , and i cold started it today, 22F and it idled fine with a carb. I think people worry about cams being too big to idle Valve springs (oil temp) need to warm up before you get on it, thats the real worry. I a 408 i think you'll be more than fine.

dixonk

iTrader: (8)

Ya I didn't doubt it. Just I like to drive it every chance I get. Car has 99,000 miles on it Just don't want it to be a chore to start it and drive it.

Shawn MacAnanny

iTrader: (12)

I drove my 346 465/422 ls6 every day for 15,000 miles. 238/242 608/612 115lsa every day no problem. I'd drive my currenty carbed setup every day if i could fix the stupid fuel gauge/sender problem. Big cams are far more driveable than people think.

dixonk

iTrader: (8)

I had that same cam with my F1C setup it ran pretty good.

s346k

iTrader: (4)

haha apparently. either way, the car will sound OK, not what i'd call angry or rowdy, and should make decent power.

dixonk

iTrader: (8)

I guess I will find out next week.